The same source (who did not wish to be named) suggested that, given the food industry's heavy reliance on recycled grades, there would be little that most companies could do in the short-term to move to virgin board.
In March, following UK media report on mineral oil traces showing up in migration tests, most of the paper and board sector took refuge in hastily convened meetings and official statements.
David Workman, director general of the Confederation of Paper Industries (CPI), said: "This research has to be taken seriously, but it has not been corroborated by any other academic institutions. Food standards agencies across Europe have said we should continue to use recycled fibre in packaging."
Issue known for a couple of years?
But the industry source said: "One reputable European test house told me that this has been around for a couple of years, that it has been an issue and one that they have been testing on for a while."
Depending on how 'new' is defined, that would also cast doubt on the ProCarton European association's official assertion that this is "a new concern".
It seems clear that the German Risk Assessment Bureau knew about the initial research by the end of 2009. A first paper was published by a government-run laboratory in Zurich at around that time, followed by more conclusive evidence in February 2010.
In the short- to medium-term, the real health risks do not appear to be serious, especially since food is inside a liner or bag and never in direct contact with recycled board. And to date, the UK media response has been relatively balanced.
But the source said: "Given corporate social responsibility undertakings under the Courtauld Commitment, for instance, this throws quite a major spanner in the works".
Brandowners blame newsprint inks
Brandowners have blamed newsprint inks for the problem, and said they will source newsprint-free recycled grades. Workman suggested: "Newspapers and magazines should be collected and sorted separately."
But the industry source said: "It's certainly not clear-cut that it's coming from newsprint. Most newspapers have in any case moved over to vegetable-based inks."
In a statement, ProCarton said: "Eliminating the root cause by phasing out the use of mineral oil-based printing inks and chemicals in both packaging and printed papers is the most sustainable option."
According to Workman, board converters such as David S Smith group have already begun to use inks which avoid mineral oils. But there is no easy short-term solution.
"Even if people chose to shift from recycled to virgin board, that would cause an imbalance in the supply chain, and prices would go up," said the source. "As things stand, it's doubtful that there would be enough virgin board available."
Around half of the board used in all consumer markets is estimated to be recycled.